Evaluation of an intervention focusing on children to promote physical activity in the entire community: Feasibility, effectiveness and sustainability over time.

Regular physical activity (PA) during childhood is associated with physical, mental, emotional and social health benefits. The constant practice of PA is considered one of the best buys available in public health. The World Health Organization (WHO) recommends to perform at least 60 minutes per day of moderate to vigorous PA for children and adolescents in order to obtain health benefits. However, globally, this level of PA is hardly achieved. Children and adolescent who do not reach the recommended levels of PA are defined as physically inactive and nowadays physical inactivity constitutes a new type of pandemic. For this reason, the WHO launched a global action plan addressing physical activity with a goal of reducing physical inactivity in children and youth. The plan also included recommendation to improve individual and community health and contribute to the social, cultural and economic development of all nations. Worldwide, children and adolescents spend a significant amount of time in school and for this reason the school represents a fundamental educational setting that can play a pivotal role increasing students’ PA. Opportunities to be physically active should not be considered purely in relation to when children attend physical education classes but also making physical activity available during the school day, such as physically active lessons, and multicomponent PA interventions. Since school-based PA interventions are quite numerous, the present thesis focused on interventions delivered during school hours and that integrate small doses of PA as part of routine instruction. This type of intervention is called “Active Breaks.” Active Breaks consists of brief 5–15 minutes sessions of PA led by teachers who introduce short bursts of PA into the academic lesson. In light of this the present thesis aims to evaluate the feasibility, efficacy and sustainability of an Active Breaks intervention targeting children to promote PA.

Numerical and physical modelling of axially loaded piles for offshore wind turbines

The scope of the thesis is to broaden the knowledge about axially loaded pipe piles, that can play as foundations for offshore wind turbines based on jacket structures. The goal of the work was pursued by interpreting experimental data on large-scale model piles and by developing numerical tools for the prediction of their monotonic response to tensile and compressive loads to failure. The availability of experimental results on large scale model piles produced in two different campaigns at Fraunhofer IWES (Hannover, Germany) represented the reference for the whole work. Data from CPTs, blow counts during installation and load-displacement curves allowed to develop considerations on the experimental results and comparison with empirical methods from literature, such as CPT-based methods and Load Transfer methods. The understanding of soil-structure interaction mechanisms has been involved in the study in order to better assess the mechanical response of the sand with the scope to help in developing predictive tools of the experiments. A lack of information on the response of Rohsand 3152 when in contact with steel was highlighted, so the necessity of better assessing its response was fulfilled with a comprehensive campaign of interface shear test. It was found how the response of the sand to ultimate conditions evolve with the roughness of the steel, which is a precious information to take account of when attempting the prediction of a pile capacity. Parallel to this topic, the work has developed a numerical modelling procedure that was validated on the available large-scale model piles at IWES. The modelling strategy is intended to build a FE model whose mechanical properties of the sand come from an interpretation of commonly available geotechnical tests. The results of the FE model were compared with other predictive tools currently used in the engineering practice.